Thermodynamic process and apparatus



Jan. 2-2, 1946. J. R. ROEBUCK THERMODYNAMIC PROCESS. AND APPARATUS 1941 2 Sheets-Sheet 1 Filed March 13 Jo/m R. R0 e19 uck I J. R. ROEBUCK THERMODYNAMIQ PROQESS AND APPARATUS Jan, 22, 1946.

Filed March 13, 1941 2 Sheets-Sheet 2 John R Roebuck fimaaqd A v 3 v v 3 aw z a 25 4 .1 H m v 3 M M mi M a 4 e F 2 Z 2 Z m Iv P/ hw E mw w w C6 to am I principle of operation;

Patented Jan. 22. 1946 UNITED STATES PATENT OFFICE THERMODYNAMIC raocass AND APPARATUS John R. Roebuck, Madison, Wis. Application March 13, 1941, Serial No. 383,146

22 Claims.

This invention relates to a thermodynamic process and apparatus and more particularly to a process and apparatus wherein work is trans-- formed into heat energy or vice versa. The invention in certain present preferred forms may beembodied in either a heater or a refrigerator and a single apparatus may be employed for both heating andrefrigeratlon. The invention effects heat transfer at high emciency and consequently at low cost.

The invention will be described as embodied in a refrigeration process and apparatus in which a flowing gas is subjected to centrifugal action and thereby compressed, after which the compressed gas is expanded with attendant cooling. Preferably the gas being compressed by centrifugal action is subjected to a cooling medium so that the compressed gas is at a temperature lower than the temperature which it would otherwise attain. The cooling efiect may be sufilcient to bring about substantially isothermal compression, whidh is desirable for most efllcient' results. when the thus compressed gas is expandedrelatively low temperatures can be obtained.

Preferably the gas serving as the refrigerant in a refrigeration apparatus flows or is recirculated through the apparatus, being centrifugaliy compressed while heat is-abstracted therefrom and'then being expanded and passing through invention will become apparent as the following description of a present preferred embodiment of the invention and a present preferred method of practicing the same proceeds. I

In the accompanying drawings I have shown a present preferred embodiment of the invention and have illustrated in present preferred method of practicing the same, in which:

Figure 1 is a diagram to Figure 2 is a cross-sectional view of apparatus for carrying out the invention, the section being taken axially therethrough:

aid in explaining the partly in transverse cross section, the section. being taken on the line III-III of Figure 2; 7

I Figure 4 is a transverse cross-sectional view t ran on the line IVIV of Figure 2; and

Figure 5 is a diagram indicating the manner in which the gas flows through the apparatus.

Referring now more particularly to the drawings and referring first to the diagram Figure 1, there is shown in suchflgure a bent tube abcdef provided with bearings B on ab and ef, the tube intermediate the bearings being of generally U form at bcde. Let it be assumed that the tube may be rotated very rapidly in the bearings B.

. Let a moderate flow of air be introduced at a.

:As the air passes along b'c outwardly from the axis ab-ef it will be subjected to a centrifugal force toward 0 which compresses the air along be and in cd to a pressure above that in ab and raises its temperature. As' this compressed warmer air moves back toward the axis along de it is progressively relieved of the centrifugal force and expands back to its former pressure and temperature by thetime it enters e].

Now putin be and, if needed, somewhat into ed a coil of pipe supplied with a cooling liquid by inlet and exit tubes along bv and which is circulated through the coil. Now as the gas is compressed. along be at least a portion of the heat of be produced by the centrifugal forceand hence by the second law of thermodynamics for the Figure 31s a view partlyin end elevation and 66 lifting of the heat from the temperature of the V compression will be absorbed by the cooling liquid and carried away. Assumethat the cooling eifect is sufllcient to maintain the temperature of the gas during compression. substantially constant.

In such case the compressed gas approaches 0. with approximately the same temperature as it had at b and prior to compression and as it expands adiabatically along de the temperature of thegas is considerably reduced. The temperature drop will depend on the ratio of the pressures at d and e and the character of the gas used. Under favorable circumstances a temperature drop of about C. may be obtained.

The gas along de, being colder at corresponding pointsthan the gas along cb, will be denser also. Thus under flowing conditions the pressure gradient along de will be greater than that along for flow to be maintained the pressure of the gas at entry at. a must be sufficiently greater than the pressure at f to cvercomethis opposing pressure and also to overcome the friction of the gas in the tube. The mechanical energy provided by this raised pressure at a is also that required discharge gas to that of the liquid absorbing the heat of compression.

The mechanical system just explained com- I ly. In a steady running state every gas particle in moving from b to c acquires substantial kinetic energy due to the high circumferential velocity Along at! this kinetic energy does not change. As

the gas particle moves back toward the axis along dc it loses this ener y to the tube. Since the number of particles in unit time moving out across any cross section in he must be exactly equal to the number moving in across any cross I section in do the steady flow of the as makes no major demands on the rotary energy of the tube. If u is the angular velocity of be and dc and be equals tie equals r, then the work done by the rotor in compressing a unit mass of gas in be is A6 7 Since this work is the product of the force and the displacement along be and the force is identical point for point as along ed the work extracted by the rotor from unit mass of gas along do is also /zw f As a first approximation the drop in temperature along de is given by where is the mean specific heat of the as in heat units.

The process above described is close to thermodynamically reversible. If with all the conditions of pressure, temperature and how in the steady state described above the pressure supplied at a a is alone decreased 2. little the flow of gas will reverse, going now from 1 towards a, abstracting heat from the liquid flow and delivering the gas at a with a pressure raised over that at f and thus converting some heat into mechanical work.

If now with a suitable supply of gas at f to maintain the reversed flow the fluid entry temperature be raised a little the flow will be accelerated so that the pressure previously at a may be restored and the flow remain reversed. Thus by manipulation of the pressure (work) and temperature (heat) variables the process may be run in either direction with relatively small changes. The cooling liquid is also compressed and expanded as it moves out to the periphery and back again. The temperature of most liquids rises on compression but by only a small fraction of that experienced by gas. Since liquid normally is much denser than gas it rises 'in pressure in the will be less dense than the outgoing liquid and.

thus will be driven around. its circuit with very considerable pressure. The energy for this driving, as in ordinary convection flows, will be drawn from the heat energy causing the expansion making the return liquid less dense.

In Figures 2, 3 and 4 of the drawings I have shown more or less diagrammatically one form of apparatus which I term a rotorr-cooler. There is provided a heavy stationary sectional metal casing 2. This casing is formed'to provide a generally cylindrical chamber 3 within which a rotor designated generally by reference numeral generally cylindrical shape with axial trunnionaeeasss I like hollow projections 6 at its opposite ends. 7

These trunnion-like projections 6 are disposed within bearing portions I of the casing 2. The jacket is made of exceptionally strong material, 5 as, for example. chrome-nickel steel, and is adapted to rotate with moderate clearance in the casing 2. The casing 2 allows the rotor to be run in a vacuum and serves as a guard against flying parts injthe event of failure.

There are provided two coaxialpipeaan inner pipe 8 and an .outer pipe 9, which extend into the rotor axially from one end thereof. The cooling medium is adapted to enter through the pipe 8 and to leave outside the pipe 8 but within the pipe 9. The casing 2 has an extension l0 provided with a connection H to the pipe 6 and a connection 12 to the pipe 9. The pipe 8 passes axially into the packet 5 and extends therethrough for'the greater portion of the length of the jacket. Mounted in the jacket and extending transversely of the axis of the rotor is a baffle l3. The baflie may be attached to the jacket 5 bybrackets (not shown) fastened to the interior of the jacket and to the bafiie. The bafie is preferably imperforate and of circular shape with its periphery spaced somewhat from the inner peripheral surface of the jacket as shown in Figure 2. The pipe 8 extends through the jacket 5 to a point immediately in front of the baflie l3 where it enters an inlet manifold l4. The-manlfold comprises a central hub or connecting portion into which the pipe 8 extends and a plurality, for example, eight, of radially outwardly extending-pipes 15. The pipes I5 are equally spaced circumferentially of the manifold. Each oi the pipes I 5 extends strai ht out parallel to the baflie l3 substantially to the periphery of the baffle where it merges into a coil i6 which extends about the axis of the rotor and also progresses longitudinally of such axis from top to bottom viewing Figure 2.- Thus there are actually as many individual coils as pipes 15 extending spirally within the jacket 5 and interfitting with one another.

Disposed within the jacket 5 and suitably supported therein as, for example, by brackets connected with the Jacket and by spacers, is a pluralit of coaxial perforate metal cylinders. In Figures 2 and 3 these cylinders are designated, re-

spectively, by reference numerals I! to 2B, inclusive, starting with the inside cylinder and proreasing outwardly. The perforations in the cylinders are preferably narrow slots running circumferentially. for short angular distances and are staggered as shown in Figure 2. They serve as bailles for directing the gas flow in contact with the coils and they also assist in positioning and spacing the coils. The outer wrap of each coil is wound about the cylinder 26 from top to bottom viewing Figure 2. Adjacent the bottom of the jacket 5 each coil then passes inwardly and is wrapped from bottom to top viewing Figure 2 about the cylinder 25 and within the cylinder 26. Thus the coils progress gradually back and forth along the axis of the jacket 5 and. also toward such axis. Each of the coils enters an outlet manifold 21 similar to the inlet manifold l5 except that provision is made for passage through the manifold 21 of the pipe 8. Connected with the manifold 2'! to receive the outflowing cooling medium and also disposed about the pipe 8 as above described is the pipe 9. Thus the cooling medium enters through the connection H, passes upwardly viewing Figure 2 through the pipe 8 to the manifold ,thence through the pipes l5 and escapes the coils is. and into the manifold 21 and out through the pipe 9 and the connection it. p

. The casing 2. is provided with ages inlet 23 communicating with the interior of the lower projection t of the jacket viewing Figure 2.

enters through the inlet 28 and the lower hollow projection 6 and thence passes outwardly among the coils it through the perforations in the cylinders ll to 26, inclusive. The diagram Figure 5 indicates how the gas flows outwardly through the perforations in the cylinders W to 23', inclu sive, and among the coils. in cross section on the line III-III of Fimlre 2 and does not show clearly the path of the gas. because of the fact that the coils are inclined to the axis of the rotor.

Radial septa 553 which extend longitudinally of the axis of the rotor are Figure 3 is partly creases in successive layers toward the periphery. Moreover,- the huge artificial gravit field greatly exaggerates convective movement in the gas. Thus any small mass of gas cooled by contact with the coilsbecomes thereby denser than its neighboring use d moves violently outwardly. The

cooling aces oi the coils are thus swept by movement oi the surface gas layer and the heat exchange is greatly accelerated. Thus th the ment' combim to 1 eflective.

provided to assist in distributing gas circumi'erentiailyof the rotor and insure that the gas will I always move around with the same angular speed as the rotor. Four such septa are preferably employed, although the number may be increased or decreased. The gas finally passes through all of the cylinders and. reaches the inner peripheral surface of the jacket 5 whence it, passes along such surface upwardly viewing Figure 2 past the edge of the'baflle l3 and thence inwardly toward the axis of the rotor through a passage is within which are four radial septa 3d and out axially of the rotor and upwardly viewing Figure 2 through the upper hollow projection 5 of the jacket 5.

- During such passage the gas is cooled as above explained and the relatively cold gas passingout through the upper hollow projection t is used for refrigeration in any well known manner.

A means for driving the rotor is shown 'diagrammatically in Figure 2. The casing 2 has a cylindrical portion is which may be the casing of a high frequency induction motor, the field magnets of. the stator of which are shown at 3| and the squirrel cage rotor of which is shown at 32. The motor is supplied with alternating current of suflicient frequency to drive it at high speed.

The rotor 32 of the motor is fastened directly to the pipe 9 and upon operation of the motor the mass contact of the gas and its convective movemake the heat exchange very For the e the cooling obtained is a func:

'tion oi is, that is of the lineor peripheral velocity Bo lg asar is kept unchansed the diameter and length of the rotor may be determined .by the cunt of as to be passed through it.

The cooling could also be obtained by using several Jets arranged" symmetrically about the periphery to discharge the gas tangentially in the. opposite direction to the linear peripheral velocity, so driving the rt. tor and cooling the gas. finch Jets do not have 102% efllciency and the expansion of the gas as above explained is preferred.

For particular purposes any gas having appropriate properties may be passed through my rotor cooler to obtains particular temperature drop. Any liquid adapted to the pressure and temperature situation involved may be used as the cooling medium. The cooling may be used for any purpose for which cooling is needed or desirable.

A rotor may be built within the strength of available materials to (1) use argon to-go from temperatures readily and cheaply available with ice machines (minus 40= C.) to nearly the boiling temperature of liquid air-or nitrogen or to the boiling temperature of liquid oxygen, (2) use I neon to go from the nitrogen, boiling point to the neon boiling point, (3), use helium to go from the neon boiling point to the hydrogen boiling point and (4) use helium to go from the hydrogen boiling point to the helium boilin point. Thus it is possible to use my refrigeration process and apparatus for the cooling and air conditioning of pipe 9 is turned thereby. Thus the pipe 9 serves as the driving shaft for the rotor. No attempt has been made to show structural details which may be employed to fasten together the various parts and provide sufflcient strength to enable the device to'operate satisfactorily at high speeds. If constructed as shown in the drawings the device will operate as described and in actual quantity production the parts will be designed and assembled in accordance with goodengineering practice.

Instead of employing an induction mater for driving the rotorany other suitable driving means may be employed, as, for example, a synchronous single or multiple phase motor driven by high frequency alternating current or a de Level type air or steam turbine. The cooling fluid may be water, alcohol or other light mobile fluid.

' As the'gas moves outwardly within the rotor it is guided by the perforate cylinders and septa so as to flow parallel to the coils in each layer for short angular distances before advancing to the I next outer layer. If these angular distances be kept alike the linear distances through which the gas moves increase with the radius. Since the work done in compressing the gas along the radius 7 increases proportionately with the radius the heat to be transferred per unit area of tube remains the same. Since the gas density increases with radius the gas velocity past the adjacent metal parts debuildings, the cooling of refrigerators, the production of ice, the recovery by cooling of vapors as casing head'gasolene and laundry cleaning fluids, the cooling. of reaction vessels in chemical work. the cooling of gasesfor their ultimate liquefaction and many similar uses.

It is possible to use the heat delivered by a refrigerati'on machine for the heating of buildings.

-When coal is burned under the best conditions in a modern power plant the work resulting ifsupplied to an eifective refrigeration machine ,will allow of raising a much larger quantity of heat than that coming from the burning of coal over or is preferably arranged somewhat differently from the rotor cooler. The gas should be compressed adiabatically (instead of nearly isothermally) and the resultant higher temperature heat will be exchanged with the liquid flow only near theperiphery of the rotor, with the liquid flow so adjusted that as nearly asjpossible it ex changes temperatures with the hot gas. The gas after adiabatic expansion may be used to freeze water to restore the heat content to the gas. Cold outdoor air could be used for its heat supply and the complication in the use of the water avoided with the accompanying loss of power efliciency. While I have shown and described apresent preferred embodiment of -the invention and a present preferred method of practicing the same it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.

'I claim:

1. Thermodynamic apparatus comprising a rotor, means for rotating the rotor, means for guiding a flowing gas generally axially into the rotor during rotation of the rotor, thence generally away from the axis of the rotor, thereafter generally toward the axis of the rotor and thence generally axially. out of the rotor at the end of the rotor opposite that at which the gas entered and means rotating with the rotor for guidinga flowing thermoconductive .substance generally axially into the rotor during rotation of the rotor asoasss of the enclosure and gulding'the cooling liquid while within the enclosure in thermoconductive relationship with the gas.

6. A thermodynamic process comprising flowing into, within and out of a rotating enclosure a gas and a cooling liquid, guiding the gas while within the enclosure generally away from the axis of the enclosure and substantially compressing it and thereafter guiding the gas while within the enclosure generally toward the axis of the en-- closure and guiding the cooling liquid while within the enclosure in thermoconductive relationship with the gas.

'7. Thermodynamic apparatus comprising a rotor, means for rotating the rotor, a conduit within the rotor rotating therewith and having an inlet and an outlet extending from the rotor generally along its axis so that a thermoconductive substance can be circulated in the conduit during rotation of the rotor, means for guiding a flowing gas into the rotor during rotation of the rotor, means for guiding the gas within the rotor in th'ermoconductive relationshipwith said conduit but segregated from said thermoconductive and while within the rotor in thermoconductive erally axially out of the rotor at the same end thereof as that at which the thermoconductive substance entered the rotor.

2. Refrigeration apparatus comprising a ro-' tor, a baflle within the rotor extending transversely of the axis thereof, means for guiding a gas generally axially into said rotor, around the edge ofsaid baflie and thence generally axially out of said rotor at the end thereof opposite the relationship with the flowing gas and thence genend at which said gas entered and cooling means ing gas into, within and out of the enclosure during rotation of the enclosure and while within the enclosure in thermoconductive relationship with said conduit and means for rotating the enclosure at such very high speed as 'to substantially compress the gas by centrifugal action.

4. A refrigeration process comprising circulating a coolant in a sinuous conduit disposed withr in and rotating with a rapidly rotating rotor and simultaneously flowing a gas through said rotor while first guiding the gas generally away from the axis of the rotor in thermoconductive relationship with the outside of said sinuous conduit and thereafter guiding the gas back toward the axis of therotor while out of thermoconductive relationship with the outside of said sinuous con-v duit.

5. A thermodynamic process comprising flowing into, within and out of a rotating enclosure a gas and a cooling liquid, guiding the gas while within the enclosure .generally away from the axis of the enclosure and substantially compressing it and thereafter guiding the gas while within the enclosure generally toward the axis of the enclosure, delivering the gas from the enclosurein a direction generally parallel to the axis substance, the gas being compressed while within the rotor by centrifugal action due to rotation of the rotonand means for delivering thegas from the rotor when the gas is at or adjacent the axis of the rotor.

8. Thermodynamic apparatus comprising s rotating enclosure and meanstherein rotating with the enclosure for guiding separately two flowing substances and connections with said means for guiding said substances into and out of the enclosure during rotation of the enclosure, said connections comprising generally axial 1 x at opposite ends of the enclosure and annular passages surrounding at least one of said generally axial passages.

9. A thermodynamic process comprising subjecting a gas flow to centrifugal force while (1) guiding the flow generally radially away from the axis of revolution, during which the radially increasing centrifugal force substantially compresses the flow, tending to heat it, and (2) guiding the flow radially toward the axis of revolution, during which the radially decreasing centrifugal force allows the flow to expand, tending to cool it, and conducting a liquid flow to absorb theheat of compression in thermoconductive relationship but out of contact with the gas flow during the compressional movement of the gas away from the axis.

10. A refrigeration process comprising subjecting flowing gas to centrifugal action while (1) guiding the gas generally away from the axis of centrifugal action, during which the progressively increasing centrifugal action substantially compresses the gas, tending to heat it, and (2) guiding the gas generally toward the axis of centrifugal action, during which the progressively decreasing centrifugal action allows the gas to expand," tending to cool it, and conducting a liquid coolant in thermoconductive relationship with the flowing gas where the gas is being guided generally away from the axis of centrifugal action during the subjecting of the gas to centrifugal action.

' 11. A refrigeration process comprising subjecting flowing gas to centrifugal action while (1) guiding the gas generally away from the axis of centrifugal action, during which the progressively increasing centrifugal action substantially compresses the gas, tending to heat it, and (2) guiding the gas generally toward the axis of cencreasing. centrli pand, tending to 001 it, andcirculating a liquid decreasing centrifugal action allows the gas to expand, tending to cool it, and ext heat. from the gas by a liquid coolant where it is helnuguided generally airway :irom' the axis oi centrifugal actionaxis a trim, tnd nndlns tne ceountgin thermoconductive relationship with the has cull where the gas is loeinggulded within the rotor generally away from the axis or the rotor.

12. A reirigeratlon-processcomprislng suhiecting flowing gasto centrifugal action while (1) guiding the gas generally away from the axis of centrifugal action, during which the progressively increasing centrifugal action substantially compresses the gas, tending to heat it, and (2) tritugal action, during which the progressively decreasing centrifugal action allows the gas to expand, tending to cool it, and cting heat from the gas by a liquid coolant whereit is being gindedgenerally away from the axis of centrih al action to such an extent as to maintain the temperature oi the gas generally the same when it reaches the point-moat rem'ots'irom th'e' axis of centrifugal action as prior to being guided generally away from the axis of centrifugal action.

13. A refrigeration process comprising suhleoting flowing gas to centrifugal action while (1) guiding the gasgenerally away from the axis of increasing centriiugal action substantially compresses the gas, tendingto heat it, and (2) guiding the .-.gas generally toward the axis of centrifugal action, during which the r vely de-.

a1 action allows the gas to excoolant in a co uit in thermoconductive relationship with the gas and thereby extracting heat from the gas during the subjection of the gas to centrifugal action and prior to sald'expansion and cooling thereof. 1

' centrifugal action, during'which the progressively 1 17. Thermodynamic apparatus comprising a rotor, means for rotating the rotor, a conduit within and rotating with the rotor and having an inlet and'anoutlet. extending irom the rotor generally along its axis so that a thermoconducthis substance can be circulated in the conduit during rotation oi) the rotor and means for guidinga flowing gas into," within and out of the guiding the gas generally toward theaxisoi can rotor during rotation of the rotor and while within the rotor successively (1) generally in a direction away from the axis or the rotor and (2) generally in a direction toward the of the rotor and while mo in one only oi said directlons'in thermoconductive relationship with said conduit.

and an outlet extending lrom the rotor generally along its axis so that athermoconductive substance can be circulated in the coil during rota tion of the rotor and means ior guiding a flow: ing gas into, within and out of the rotor during rotation oi the rotor and while within the rotor successively (ll generally in a direction away from theaxis oi the rotor and (2) generally in a direction toward the sins of the rotor and while moving in one only of said directions passing successively about the convolutionsoi said coil.

14. A refrigeration process comprising subjectmg a gas in a condultto a pressure diflerence to cause it to flow in said conduit, while the gas is thus flowing in said conduit subjecting it to centrliugahcompression while guiding it generally away from the centrifugal axis, the progressively'increasing centrifugal action substantially i compressing the gas, while thus guiding the gas bringing it into 'thermoconductive relationship but not into contact with a, heat extracting liquidsothat the heat of compression of the gas is at least largely carried away by the liquid whereby the temperature of the gas is maintained approximately constant and thereafter guiding the gas generally toward the centriiugal axis, during which the progressively decreasing centriiugal action allows the gas to expand, tending to cool it,j and delivering the gas-adjacent the centrifugal axial 1 15. A thermodynamic process comprising flowing into, within and out oia rotating rotor and rotating therewith a working substance consisting entirely of gas and which throughout the process remains entirely in gaseous i'orm, and a thermoconductive substance, guiding the gas 19. Thermodynamic apparatus comprising a rotor, means for rotating the rotor, means for guiding a flowing gas into, within and out of the. rotor during rotation of the rotor and while within the rotor successively (1) generallyaway from the axis of the rotor and (2) generally toward the axis of the rotor, means for delivering the gas from the rotor when the gas is at or adjacent the axls of the rotor and means for guiding a flowing thermoconductive substance into, within the rotor, said means for guiding the flowing thermoconductive' substance guiding suoh substance out of the rotor generally along the axis of the rotor. 1

20. Refrigeration apparatuscomprislng a 1'0- tatable enclosure, means for rotating the enclosure, a conduit within the enclosure and having an inlet and an outlet extending from the enclosure generally along it axis so that a coolant can be circulated in the conduit during rotation 01" the enclosure and means rotating with the enclosure for guiding a. flowing gas into, within and out of the enclosure-during rotation oi the enclosure'and while within the enclosure successively (1) generally away from the axis of the enclosure and in thermocondu'ctive relationship with said conduit and (2) generally toward the axis of the enclosure.

and a coolant, guiding the gas while within the rotor successively (1) generally away from the axis of the rotor and (2) generally toward the 21. Thermodynamic apparatus comprising a rotor, a baifle within the rotor extending transversely of the axis thereof, means for guiding a fluid generally axially into said rotor substantially at the axis of the rotor, around the edge oi. said ballle and thence generally axially out oi said rotor at the end thereof opposite the ,6 1 accuse end at which said fluid entered and a heat transfer conduit with which said fluid is adapted to contact within said rotor at one side of said home.

22. A 'thei modynamic process comprising subjecting a gas to centrifugal action in a rotating enclosure and thereby compressing the gas, simultaneously with saidcompressing passing a 

